Intramolecular Electron Transfer between Terminal 1,4-Dimethoxybenzene Units in Radical Cations with a [2.2](1,4)Naphthalenophane, [2.2](1,4)Anthracenophane, and Pentacene Skeleton

Anti‐[2.2](1,4)pentacenophane: A Covalently Coupled Pentacene Dimer

“…The current of the first oxidation peak is proportional to the square root of the scan rate, indicating a diffusion‐controlled electron transfer. The potential splitting (Δ Ē =0.23 V) is larger than observed for the tetramethoxy derivative of the [2.2](1,4)anthracenophane and almost as large as in the corresponding naphthalenophane 4c. A direct comparison with these compounds bearing electron‐donating substituents, however, is hampered by possible substituent effects.…”

“…The interaction between the anthracene chromophores has received significant attention and was studied by absorption and fluorescence spectroscopy,3 by ESR or ENDOR spectroscopy in radical anions or cations 4. Electronic interaction between the two aromatic ring units was also probed by cyclic voltammetry 4b,c. For the oxidation of the naphthalene4c and the reduction4b and oxidation4c of anthraceno systems, splitting of voltammetric peaks was observed: the presence of a radical ion in one unit renders the electron transfer to or from the second unit more difficult.…”

“…Electronic interaction between the two aromatic ring units was also probed by cyclic voltammetry 4b,c. For the oxidation of the naphthalene4c and the reduction4b and oxidation4c of anthraceno systems, splitting of voltammetric peaks was observed: the presence of a radical ion in one unit renders the electron transfer to or from the second unit more difficult. The effect seems to decrease with increasing size of the units, and is stronger for the syn as compared to the anti isomer 4c…”

Beyond Simple Substitution Patterns – Symmetrically Tetrasubstituted [2.2]Paracyclophanes as 3D Functional Materials

“…Scope of the substitution pattern of substituted dibenzoequinene, and tetramethoxy PC derivatives 23 and 24 by Neugebauer and co‐workers which were compared with 19b …”

“…Neugebauer and co‐workers utilized bis(ps‐meta)‐ortho CP derivatives to investigate the transannular delocalization in radical cations . To achieve this, they synthesized and studied three species of PCs, 19b , 23 and 24 by means of EPR and ENDOR spectroscopy.…”